Search Google Appliance

Texas Instruments TI-2550 III Handheld Electronic Calculator

Description

In 1972 Texas Instruments began selling electronic calculators under its own name. The first of these was the Datamath or TI-2500. Over the next few years, TI sold modifications of the TI-2500 that had different forms of battery (such as the TI-2500B, the TI-2500II, the TI-2510, and the TI-2550III), a different color case (the TI-2510 and the TI-2550III), a key for taking percentages (the TI-2550, the TI-2550II, and the TI-2550III), and keys for additional functions (the TI-2550, the TI-2550II and the TI-2550III). This is an example of the TI-2550III.

The calculator has an array of thirty-five rectangular plastic keys. These include ten digit keys, four arithmetic function keys, a clear key, a clear entry key, a decimal point key, and a total key. Also included are a change sign key, a percentage key, four memory keys, an inverse key, a square key, a square root key, and a reverse entry (RV) key. The RV key replaced an entry in the display with the immediately preceding entry.

The on/off switch is above the keyboard on the right. A mark above it reads: TEXAS INSTRUMENTS TI-2550III. Behind this is an eight-digit blue vacuum fluorescent display.

There is a jack for a power adapter along the back edge (according to instructions for the calculator found online, this would have part number AC9310A). The back has a battery compartment that would hold a rechargeable battery pack (according to instructions for the calculator, this would have model number BP-3).

A sticker on the back of the calculator reads in part: US PAT 3819921 OTHER PATENTS PENDING (/) TEXAS INSTRUMENTS (/) TI-2550-III (/) electronic Calculator (/) Serial No. (/) 2550-III 075877. It also reads in part: ASSEMBLED IN USA. A mark below the label reads: 4576LTA.

Unscrewing four screws from the back of the calculator reveals the circuit board. The largest chip is marked: TMS1043NL (/) KBSΔ7642.

Visitor Comments

Add a comment about this object

**Please read before submitting the form**

Have a comment or question about this object to share with the community? Please use the form below. Selected comments will appear on this page and may receive a museum response (but we can't promise). Please note that we generally cannot answer questions about the history, rarity, or value of your personal artifacts.

Have a question about anything else, or would you prefer a personal response? Please visit our FAQ or contact page.

Personal information will not be shared or result in unsolicited e-mail. See our privacy policy.